Suggest Remedy For Knee Pain And Difficulty In Climbing Stairs

HI, I am 63 years old , I am 5 feet and 5 inches , my weight is 195 pounds, my knees plate which is in between knees is tear, I cannot walk more then 10 to 12 minutes and its very hard to climb stairs , but no pain. What is the best way for me. Thanks Nighat.